Software Engineer (£80k + Equity) at REVAX

This is a job that Jill, our AI Recruiter, is recruiting for on behalf of one of our customers. She will pick the best candidates from Jack's network. The next step is to speak to Jack. Job Title Software Engineer Salary £80k + Meaningful EMI Equity Company Description REVAX is a seed-stage London startup backed by leading institutions and angels, building a new class of AI-native software for tax advisory teams. Job Description As a Software Engineer at REVAX, you will work directly with founders to build and scale multi-agent AI systems. You will own features end-to-end, from prototyping LangGraph-based agents to production hardening on GCP. This role is central to transforming how major tax advisory firms research and draft complex deliverables using structured, transparent AI. Location London, UK Why this role is remarkable Work at the cutting edge of agentic AI, building production-grade multi-agent systems using LangGraph and knowledge graphs for highly regulated domains. Join a high-velocity, technical founding team at the seed stage, backed by top-tier institutions and already delivering value to major professional services firms. High-impact ownership where you define the engineering standards and security patterns required to sell sophisticated AI products to enterprise clients. What You Will Do Architect and implement multi-agent systems using LangGraph, incorporating retrieval pipelines, vector search, and Neo4j knowledge graphs for complex data modelling. Design and scale performant FastAPI services on Google Cloud Platform, ensuring high reliability, observability, and cost-efficiency for AI-driven workflows. Build enterprise-grade features including IAM, multi-tenant isolation, and audit trails to meet the rigorous security requirements of major advisory firms. The ideal candidate Has 2-3 years of experience building production software, including at least one year within a fast-paced startup environment. Demonstrates deep technical proficiency with modern Python, FastAPI, and AI technologies like RAG pipelines, vector databases, or LangGraph systems. Exhibits a high-ownership mindset and leverages modern AI coding tools like Cursor or Claude Code to ship high-quality code at speed. Who are Jack & Jill? Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support. And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate. How does this work? Jack's an AI agent for job searching and career coaching. He works for you. Jill is the AI recruiter working for the company. She recruits from Jack's network. If it's a match and the company wants to meet you, they'll make the intro. In the meantime, if you'd like, Jack will send you excellent alternatives. We never post fake jobs This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network. Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description. We appreciate this can make them look a bit suspect, but there isn't much we can do about it. Give Jack a spin! You could land this role. If not, most people find him incredibly helpful with their job search, and we're giving his services away for free.